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                                                                     Exhibit 5.1
                                                                     -----------

                                HALE AND DORR LLP
                                 60 State Street
                                Boston, MA 02109

                                                              September 28, 1999


Staples, Inc.
500 Staples Drive
Framingham, MA  01702

     Re:  Staples, Inc. 1998 Employee Stock Purchase Plan - II
          ----------------------------------------------------

Ladies and Gentlemen:

     We have assisted in the preparation of a Registration Statement on Form S-8
(the "Registration Statement") to be filed with the Securities and Exchange
Commission relating to 25,000 shares of Common Stock, $.0006 par value per share
(the "Shares"), of Staples, Inc., a Delaware corporation (the "Company"),
issuable under the Staples, Inc. 1998 Employee Stock Purchase Plan - II (the
"Plan").

     We have examined the Restated Certificate of Incorporation of the Company
and the Amended and Restated By-Laws of the Company, each as amended to date,
and originals, or copies certified to our satisfaction, of all pertinent records
of the meetings of the directors and stockholders of the Company, the
Registration Statement and such other documents relating to the Company as we
have deemed material for the purposes of this opinion.

     In examination of the foregoing documents, we have assumed the genuineness
of all signatures and the authenticity of all documents submitted to us as
originals, the conformity to original documents of all documents submitted to us
as certified or photostatic copies and the authenticity of the originals of such
latter documents.

     Based on the foregoing, we are of the opinion that the Company has duly
authorized for issuance the shares of its Common Stock covered by the
Registration Statement to be issued under the Plan, as described in the
Registration Statement, and such shares, when issued in accordance with the
terms of the Plan, will be legally issued, fully paid and nonassessable.
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Staples, Inc.
September 28, 1999
Page 2


     We hereby consent to the filing of this opinion with the Securities and
Exchange Commission in connection with the Registration Statement.

                                    Very truly yours,

                                    /s/ Hale and Dorr LLP

                                    HALE AND DORR LLP
